After Effects export with RGB+ alpha animation codec getting dropped frames in Premiere pro 2020

Hi there.

first time posting in the forum so not sure if i should create new thread or not but My questino relates to the RGb + alpha . I have a macbook pro brand new with 32G ram and 2.3 8 core processor and using an SSD 2000mb/s esxternal hardrives for my project.     I am layering animation lossless RGB + alpha codec from my After Effects exports  and then editing with thtem  in my Premiere 2020 timeline . The alpha channel is impoortant but its my fist time integrating After Effects files into premiere.   The problem i am having is playback and constant rendering issues. Even when i have proxies enabled and low res. i make the smallest of changes to my timeline and the render line turns yellow , i my machine wont play back the yellow lines smoothly . its got to be green render line or otherwise i get tons of dropped frames.  So my editing is painful and i cant seem to be fluid and work fast.  Also want to add that when working on another sequence without the After effects lossless animatino files i am able to play and edit 4K video , making frequent changes to a 6-10 layer timeline and even when i get yellow render lines i still can play it back smoothly without having to rerender.... Any thoughts. ? I am not 100% if my proxy files i created for the Animation codecs i made with alpha channel display or not, not sure.   The Alpha channel is displaying correctly when i toggle proxy on and off, so i presume i usesd correct setting in creating my proxy, otherwise i imagine when proxy are enabled in timeline then i would lose the transparency if i had wrong proxy setting.. apprecaite anyones help very much.. let me know if you need further info from me.. many thanks shane